Cadinols (sesquiterpenes), a tricyclic diterpenoid compound, estrone and a 19-nor-9-hydroxyandrostane were prepared using the methodology of hydroboration/carbonylation (stitching and riveting). Using the expertise developed during these studies, it is proposed to prepare racemic cortisone, (by two different routes (1,2)) optically cortisone (3), fichtelite (4), hibanone (5), kaurene (6), and an aphidicolin synthon (7). These propositions are designed (a) to carefully evaluate a new approach to steroid and natural product synthesis, (b) to provide medicinally important drugs (cortisone, etc., as well as allow for evaluation (testing) of a new class of "hetero"-steroids (borasteroids) and (c) to answer certain important chemical questions concerning the usage of carboranes in complex natural product synthesis. Projects 1 and 3 will provide cortisone by hydroboration/carbonylation of triolefinic substrates, while project 2 is designed to evaluate the effect of "remote" Lewis acid-base reactions on the steriochemical course of hydroboration. Proposals 4 and 6 (fichtelite, kaurene) are stereochemical studies differing from those of project 1, while project 5 is analogous to 2 but is really designed to sort out or reveal the electronic-factors that could be exploited during a hydroboration/carbonylation process in the form of neighboring group participation to assure a stereochemically well defined product. Project 7 is designed to reveal some structural constraints that will effect stitching and riveting. All compounds prepared will be evaluated for activity with general screening being done at Lederle's Drug Co. with certain specific types of activity (anticancer, antileukemic) being done at USC.